variable(n) Tcl Built-In Commands variable(n)
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NAME
variable - create and initialize a namespace variable
SYNOPSIS
variable ?name value...? name ?value?
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DESCRIPTION
This command is normally used within a namespace eval command to create one or more variables within
a namespace. Each variable name is initialized with value. The value for the last variable is
optional.
If a variable name does not exist, it is created. In this case, if value is specified, it is
assigned to the newly created variable. If no value is specified, the new variable is left unde-fined. undefined.
fined. If the variable already exists, it is set to value if value is specified or left unchanged if
no value is given. Normally, name is unqualified (does not include the names of any containing
namespaces), and the variable is created in the current namespace. If name includes any namespace
qualifiers, the variable is created in the specified namespace. If the variable is not defined, it
will be visible to the namespace which command, but not to the info exists command.
If the variable command is executed inside a Tcl procedure, it creates local variables linked to the
corresponding namespace variables (and therefore these variables are listed by info locals.) In this
way the variable command resembles the global command, although the global command only links to
variables in the global namespace. If any values are given, they are used to modify the values of
the associated namespace variables. If a namespace variable does not exist, it is created and
optionally initialized.
A name argument cannot reference an element within an array. Instead, name should reference the
entire array, and the initialization value should be left off. After the variable has been declared,
elements within the array can be set using ordinary set or array commands.
SEE ALSO
global(n), namespace(n), upvar(n)
KEYWORDS
global, namespace, procedure, variable
Tcl 8.0 variable(n)
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